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Old 05-21-2010, 04:33 PM   #1
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Default AFR's bouncing, car bucking

When I'm cruising around 3200rpm at 70kpa the car is surging and driving me nuts. I logged it and my AFR's bounch from 15.5 to 12:1 when I'm in this range. Is this my accel enrichment I need to play with.
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Old 05-21-2010, 04:45 PM   #2
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Well judging from the log you posted I would need to see a non-imaginary log. Please post one
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Old 05-21-2010, 04:46 PM   #3
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Want to post up your datalog and .msq?
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Old 05-21-2010, 05:13 PM   #4
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Post it so I can benefit thanks.
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Old 05-21-2010, 05:16 PM   #5
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how do I post those things
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Old 05-21-2010, 05:19 PM   #6
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At the bottom "Manage Attachments" click it.
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Old 05-21-2010, 05:22 PM   #7
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the bouncing is around record 2100
Attached Files
File Type: xls log8.xls (770.8 KB, 58 views)
File Type: msq Miata Turbo 5-20.msq (35.1 KB, 61 views)
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Old 05-21-2010, 05:47 PM   #8
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When you play the log where it's bouncing around, you can see your accel enrich is rapidly switching on and off, which is a consequence of running MAPdot based accel when your MAP signal has Tourette Syndrome. Where is your vac line to the MS sourced? If it's not already teed off the fuel pressure regulator, try that first and see if it helps.
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Old 05-21-2010, 05:51 PM   #9
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It is sourced right where they say on the TB.
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Old 05-21-2010, 06:14 PM   #10
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"on the TB" ≠ "teed off the FPR"

If you take the signal close to the throttle plate it will be jumpy.
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Old 05-21-2010, 06:45 PM   #11
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what about the port at the very back of the intake manifold. I can run a reducer off that port.
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Old 05-21-2010, 11:24 PM   #12
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Quote:
"on the TB" ≠ "teed off the FPR"
"the port at the very back of the intake manifold ≠ "teed off the FPR"

tee it off the FPR, it should help in dapening the MAP signal so it will not spike and throw it into trying to add extra fuel
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Old 05-31-2010, 03:01 PM   #13
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I believe I have the problem fixed now. Tee'd of the FPR helped but did'nt completely cure it. After some reading I put a fuel filter in the map line and know the car seems much smoother and I can't reproduce the problem. Gonna record some logs and see if my map readings look smoother as well.
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